Sleeping bag

ABSTRACT

This disclosure relates to a zipperless sleeping bag having a catenary opening for providing a user ingress to and egress from the sleeping bag and/or an integral comforter.

CROSS-REFERENCE TO RELATED APPLICATION

This nonprovisional application claims priority to U.S. Provisional Patent Application Ser. No. 61/793,109, filed on Mar. 15, 2013, which is incorporated in its entirety by reference.

FIELD

The field of the disclosure relates generally to sleeping bags. More particularly, this disclosure relates to a zipperless sleeping bag having an opening for providing a user ingress to and egress from the sleeping bag, a support member for holding the opening in a catenary manner, and/or an integral comforter.

BACKGROUND

Typically, sleeping bags are used when conventional bed and bedding are unavailable. For example, sleeping bags are used by backpackers, hikers, campers, mountaineers, and other users as portable beds or coverings. Sleeping bags are often durable sleeping coverings that provide a soft surface, insulation and weather resistance.

Consumers face a difficult task in finding a sleeping bag that is thermally efficient, comfortable, and lightweight. One type of sleeping bag is referred to as a “mummy bag”, which tends to be shaped with a lateral taper to approximate the contour of the body of a user and thereby minimize the internal volume of the bag. Mummy bags attempt to conserve heat by minimizing air movement within and from the bag. As a result, mummy bags are often suited for use in outdoor, colder ambient temperatures.

Mummy bags typically have a small generally elliptical opening suitable for a user's head to protrude from during use. In order to enter typical mummy bags, a user must unzip the bag, and then get inside the bag. Due to the tight fit, the user may find it difficult to fully zip the bag, and furthermore, the zipped bag may be uncomfortable. For example, one drawback to the mummy bag is that some users feel discomfort due to the tight fit of the bag, which may reduce the range of motion of the user of the bag. Such feeling of discomfort may be increased in parts of the user's body that are often moved during sleep such as the arms and legs of the user. Thus, some users are unable to sleep comfortably in mummy bags.

Other sleeping bags, such as rectangular-type sleeping bags, are shaped with a generally constant lateral dimension and provide a greater range of motion for the user. Such bags also typically have a zippered portion to allow the user to more easily enter the bag. However, although rectangular bags are often more spacious than mummy bags, one drawback is that the larger internal volume reduces the thermal efficiency of the bag. Moreover, rectangular bags often do no insulate the head, and are typically too large to be thermally efficient. As a result, rectangular bags tend to be better suited for use indoors or in milder outdoor temperatures.

Accordingly, a need exists for a sleeping bag that is comfortable, thermally efficient, and allows a user to sleep on their stomach, back or side comfortably.

BRIEF DESCRIPTION

In one aspect, a sleeping bag generally comprises an elongate shell defining an inner volume sized and shaped to receive a user therein. The shell has a head portion, a foot portion, a middle portion extending longitudinally between the head and foot portions, an overlying portion adapted to overlie the user during use, and an underlying portion adapted to underlie the user during use. A hood is located in the head portion of the shell. The hood includes a catenary opening such that the overlying portion of the shell adjacent the opening is spaced from the underlying portion of the shell when the sleeping bag is laid out for use.

In another aspect, a sleeping bag generally comprises an elongate shell defining an inner volume sized and shaped to receive a user therein. The shell has an overlying portion adapted to overlie the user during use, an underlying portion adapted to underlie the user during use, and an opening disposed on the overlying portion of the shell. The opening is configured to provide a user ingress to and egress from the inner volume of the sleeping bag. The opening width is less than a width of the shell.

In yet another aspect, a sleeping bag generally comprises an elongate shell defining an inner volume sized and shaped to receive a user therein. The shell has an overlying portion adapted to overlie the user during use, an underlying portion adapted to underlie the user during use, and an opening disposed on the overlying portion of the shell. A comforter is attached to the overlying portion of the shell for selectively closing the opening.

In still yet another aspect, a comforter for use with a sleeping bag includes a pair of longitudinally extending pockets.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a zipperless sleeping bag having an opening.

FIG. 2 is a top plan view of the sleeping bag of FIG. 1.

FIG. 3 is a bottom plan view of the sleeping bag of FIG. 1.

FIG. 4 is a right side elevation of the sleeping bag of FIG. 1.

FIG. 5 is a left side elevation of the sleeping bag of FIG. 1.

FIG. 6 is an end view showing a head end panel of the sleeping bag of FIG. 1.

FIG. 7 is an end view showing a foot end panel of the sleeping bag of FIG. 1.

FIGS. 8 and 9 are enlarged top plan views of a head portion of the sleeping bag of FIG. 1.

FIGS. 10 and 11 are top perspective views showing an integral comforter of the sleeping bag of FIG. 1 with the comforter being in an exterior position.

FIGS. 12-14 show a user partially placing her hands in pockets formed in the comforter of FIGS. 10 and 11.

FIG. 15 is an enlarged top plan view showing the comforter of the sleeping bag fully closing the opening.

FIG. 16 is an enlarged top plan view similar to FIG. 15 but illustrating the comforter of the sleeping bag partially closing the opening.

FIG. 17 is a perspective view of another embodiment of a zipperless sleeping bag having an opening.

FIG. 18 is a top plan view of the sleeping bag of FIG. 17.

FIG. 19 is an end view showing a head end panel of the sleeping bag of FIG. 17.

FIG. 20 is an end view showing a foot end panel of the sleeping bag of FIG. 17.

FIG. 21 is a right side elevation of the sleeping bag of FIG. 17.

FIG. 22 is a bottom plan view of the sleeping bag of FIG. 17.

FIGS. 23-25 are top views of other embodiments of a zipperless sleeping bag having an opening for user ingress and egress.

FIG. 26 is an enlarged top view of another embodiment of a zipperless sleeping bag having an opening for user ingress and egress.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now to the drawings and in particular to FIGS. 1-7, one embodiment of a zipperless sleeping bag is designated in its entirety by the reference number 1. The sleeping bag 1 comprises an elongate shell, indicated generally at 3, that defines an inner volume sized and shaped to receive a user therein. The shell 3 has a head portion 5, a foot portion 7, and a middle portion 9 extending longitudinally between the head and foot portions (FIG. 2). In addition, the shell 3 has an overlying portion 11 (FIG. 2), which is adapted to overlie the user during use, and an underlying portion 13 (FIG. 3), which is adapted to underlie the user during use. The zipperless sleeping bag 1 is free from any zippers. The sleeping bag 1 illustrated in FIGS. 1-7 is a “regular” size bag adapted to fit users up to 6 feet tall. It is understood that the sleeping bag 1 can have any suitable size (e.g., shorter, longer, wider, narrower) and can be adapted specifically for men, women or youths.

The shell 3 further comprises a head end panel 15 (FIG. 6) located in the head portion 5, a foot end panel 17 (FIG. 7) located in the foot portion 7, and a pair of spaced side panels 19 (FIGS. 4 and 5) located in the middle portion 9. The side panels 19 extend longitudinally between the head end panel 15 and the foot end panel 17. The head end panel 15, the foot end panel 17, and the side panels 19 are stitched into the shell 3 between the overlying portion 11 and underlying portion 13. As a result, the panels 15, 17, 19 collectively provide vertical expansion of the shell 3 thus adding inner volume to the sleeping bag 1. It is contemplated that in some embodiments, the panels 15, 17, 19 can be omitted.

With reference again to FIGS. 1 and 2, a hood, indicated generally at 21, is located at the head portion 5 of the shell 3. The hood 21 is adapted to receive and surround the head of a user. The overlying portion 11, and more specifically the hood 21 in the illustrated embodiment, includes an opening 23. The opening 23 is suitably large enough to provide the user ingress to and egress from the inner volume of the sleeping bag 1. In other words, the user is able to enter and exit the inner volume of the sleeping bag 1 through the opening 23. Thus, no zippers or other fasteners are needed for the user to enter or exit the inner volume of the sleeping bag 1.

As seen in FIG. 8, the opening 23 is defined by a continuous inner edge of the overlying portion 11. Specifically, the opening 23 is defined by a continuous inner edge having an upper edge portion 24, a lower edge portion 26, and two side edge portions 28, 30 (i.e., a right side edge portion (28) and a left side edge portion (30) as viewed in FIG. 8). In the illustrated embodiment, each of the edge portions 24, 26, 28, 30 are rounded (i.e., non-straight) thereby defining a rounded opening. As seen in FIG. 2, the right and left side edge portions 28, 30 are longer (i.e., have a greater extent) than the upper and lower edge portions 24, 26. Moreover, in the illustrated embodiment, the upper edge portion 24 is slightly longer than the lower edge portion 26. As a result, the illustrated opening 23 is a rounded opening and more specifically, an oval or ovate opening. It is understood that the lower edge portion 26 can be longer than the upper edge portion 24 and still form the ovate opening 23. Other embodiments of a sleeping bag having an ovate opening are illustrated in FIGS. 18-26.

In another suitable embodiment, the opening 23 can be generally elliptical (see FIG. 23). In such an embodiment, the upper and lower edge portions 24, 26 can be generally equal in length and the right and left side portions 28, 30, which are longer than the upper and lower edge portions 24, 26, can be generally equal in length. It is understood that the upper and lower edge portions 24, 26 can be omitted such that the right and left side portions 28, 30 connect to each other at their respective ends. In yet another suitable embodiment, the opening 23 can be circular. In such an embodiment, all of the edge portions 24, 26, 28, 30 are generally equal.

It is understood that, in some embodiments, the opening 23 can be a different suitable shape (e.g., pentagon, hexagon, octagon). It is also understood that the opening can be partially rounded (e.g., truncated oval, truncated ellipse) or non-rounded (e.g., square, rectangular) in other embodiments and without departing from some aspects of this invention.

With reference now to FIG. 2, the opening 23 has a first diameter D1 and a second diameter D2. In the illustrated embodiment, the first diameter D1 is the distance between the upper edge portion 24 and the lower edge portion 26, and the second diameter D2 is the distance between the right side edge portion 28 and the left side edge portion 30. While the first diameter D1 is shown longer than the second diameter D2 in FIG. 2, which is a relaxed position of the sleeping bag 1, it is understood that the first and second diameters D1, D2 can be readily manipulated as a result of the sleeping bag 1 being flexible. As illustrated in FIG. 8, for example, the sleeping bag 1, and more specifically the edge portions 24, 26, 28, 30 defining the opening, can be manipulated so that the first and second diameters D1, D2 are generally equal or the second diameter D2 is longer than the first diameter D1.

As seen in FIGS. 2 and 8, the opening 23 is defined entirely on the overlying portion 11 of the shell 3. Thus, the opening 23 is spaced from the head end panel 15 and the side panels 19. In one suitable embodiment, the opening 23 is spaced from the head end panel 15 (i.e., the distance from the upper edge portion 24 to the head end panel 15) from about 4 inches to about 13 inches. In the illustrated embodiment, for example, the opening is spaced about 7.5 inches from the head end panel. The opening 23, in one suitable embodiment, is spaced from each of the side panels 19 (i.e., the distance from the right and left edge portions 28, 30 to the respective side panel 19) from about 7 inches to about 12 inches. In the illustrated embodiment, for example, the opening 23 is spaced from each of the side panels 19 by about 8.5 inches. It is contemplated that the opening 23 can be spaced from the head end panel 15 and the side panels 19 by a distance different than those disclosed herein without departing from some aspects of this invention.

With reference to FIGS. 8 and 9, the head portion 5 of the shell 3 includes a support member 25 disposed between the opening 23 and the head end panel 15 and extending from one of the side panels 19 to the other. The support member 25 is attached (e.g., by stitching) along three of its edges to the shell 3. Specifically, the support member 25 is attached at its edges to each of the side panels 19 and the head end panel 15. As a result, the edge of the support member 25 adjacent the opening 23 is free. That is, the edge of the support member 25 adjacent the opening 23 is not directly attached to the shell 3. The support member 25 is configured to provide support to the head portion 5 of the shell 3 such that the side panels 19 and head end panel 15 of the shell do not collapse and the opening 23 hangs freely. Accordingly, the opening 23 of the illustrated sleeping bag 1 is a catenary opening. As such, the overlying portion 11 of the shell 3 adjacent the opening 23 is spaced from the underlying portion 13 of the shell when the sleeping bag 1 is laid out for use as seen in FIGS. 1-7.

In the illustrated embodiment, the support member 25 is made from the same material as the shell 3 (i.e., an inner layer, an outer layer, and an insulation material between the inner and outer layers) but it is understood that the support member can be made from any suitable material or materials. The illustrated support member 25 has a generally constant width along its length. It is understood however that the width of the support member 25 can vary along its length, e.g., to conform to the contours of the sleeping bag 1.

In the embodiment seen in FIGS. 1-7, the shell 3 tapers toward the foot end 7 to generally conform to the contours of the user, being broadest in the region corresponding to the shoulders of the user and narrowest or tapered in the region corresponding to the feet of the user. The tapered shell 3 provides the user a generally snug fit. By generally conforming to the user's contours when the user is substantially within the inner volume of sleeping bag 1, the sleeping bag 1 minimizes air movement, thus making the bag thermally efficient. The illustrated sleeping bag 1 can be generally categorized as a semi-rectangular bag or a tapered bag. It is understood, however, that in other embodiments the sleeping bag 1 could have less taper (e.g., a rectangular-type bag) or have greater taper (e.g., a mummy type bag).

As shown in FIG. 2, the shell 3 has an inner layer 27, which defines the inner volume of the shell 3, and an outer layer 29, which defines the exterior of the shell. The inner layer 27 is adapted to receive a user within the inner volume of the sleeping bag 1. An insulation material (not shown) can be disposed between the inner and outer layers 27, 29 to provide warmth and softness to the sleeping bag 1. The insulation material can be attached to the inner and outer layers 27, 29 of the shell using stitch-lines. It is understood that the inner and outer layers 27, 29 can be any suitable material (e.g., polyester). It is also understood that the inner layer 27 can be made from a material different that the outer layer 29. It is further understood that the insulation material can be any suitable material (e.g., goose down, CLOUDLOFT insulation, DRIDOWN insulation) and that the amount of insulation material can be selected to achieve the desired warmth and softness.

With reference now to FIG. 3, the illustrated sleeping bag 1, and more specifically the outer layer 29 of the underlying portion 13 of the illustrated shell 3, includes a sleeve (or pocket) 31 for selectively receiving at least a portion of a sleeping pad (e.g., an open cell foam sleeping pad, an inflatable sleeping pad). In use, a suitable sleeping pad (not shown) can be inserted into the sleeve 31 thereby connecting the sleeping pad to the shell 3 of the sleeping bag 1 and inhibiting the sleeping bag and sleeping pad from become disengaged during use. For example, insertion of the sleeping pad into the sleeve 31 inhibits the user of the sleeping bag from rolling off of the sleeping pad. In other words, the sleeve 31 facilitates keeping the sleeping pad beneath the user and thus between the user and the surface upon which the sleeping bag 1 and sleeping pad lie. It is understood that any suitable sleeping pad can be used with the sleeping bag 1. For example, the sleeping pad can be tapered to generally conform to the shape of the sleeping bag 1 or can be generally rectangular. It is also understood that the sleeping pad can have a length greater to, equal to or shorter to the length of the sleeping bag 1. It is further understood that the sleeve 31 can be omitted from some embodiments of the sleeping bag 1.

With reference still to FIG. 3, a part of the underlying portion 13 of the shell 3, generally corresponding to sleeve 31, is free from insulating material. Thus, insulating material is not provided in the portion of the sleeping bag 1 adapted to receive the sleeping pad. It is understood, however, that insulating material can be provided in this part of the underlying portion 13 of the shell 3. In such an embodiment, the entire underlying portion 13 of the shell 3 would have insulating material. It is also understood that the other parts of the underlying portion 13 of the shell 3 (i.e., parts extending beyond the sleeve 31) intended to overlie the sleeping pad can also be free from insulating material. In such an embodiment, the sleeping pad provides warmth and softness to the underlying portion 13 of the shell 3.

Referring now to FIGS. 10 and 11, the sleeping bag 1 comprises an integral comforter, indicated generally at 35. In the illustrated embodiment, the comforter 35 is generally rectangular. As a result, the comforter 35 has four side edges. Two of the side edges extend longitudinally with respect to the shell 3 and the other two side edges extend transversely with respect to the shell. A portion of one of the transversely extending side edges is sewn to the inner layer 27 of the overlying portion 11 at a location spaced from the foot end panel 15. In one suitable embodiment, the comforter 35 is sewn to the inner layer 27 of the overlying portion 11 transversely across the width of the shell 3 at a location generally adjacent and below the opening 23. It is contemplated that the comforter 35 can be sewn less than the entire width of the shell. It is also contemplated that the comforter 35 can be affixed to the overlying portion 11 in any suitable manner and location. In another suitable embodiment illustrated in FIG. 24, the comforter 335 is disposed on the outer layer 329 of the overlying portion 311. In other embodiments, the comforter 35 can be detachably attached to the inner layer 27 and/or outer layer 29 of the shell 3 in any suitable manner, for example, buttons, snaps, hook and loop. In some embodiments, the comforter 35 may not be attached to the sleeping bag.

As seen in FIGS. 10 and 11, the comforter 35 has a width (i.e., the distance between the longitudinally extending side edges) greater than the width of the shell 3. As a result, the longitudinally extending edges of the comforter 35 are capable of extending transversely beyond the extent of the shell 3. In the illustrated embodiment, the comforter 35 has a length (i.e., the distance between the transversely extending side edges) that is approximately half the length of the shell 3. As mentioned above, the illustrated comforter 35 is generally rectangular. In the illustrated embodiment, for example, the length of the comforter 35 is greater than its width. It is contemplated that the comforter 35 can have any suitable size or shape.

The comforter 35 can be selectively moved from a first or interior position wherein the comforter is disposed within the inner volume of the shell 3 (FIGS. 15 and 16) and a second or exterior position, wherein the comforter is at least partially disposed outside the inner volume of the shell (FIGS. 10 and 11). In the interior position, the comforter 35 at least partially closes the opening 23 to block or otherwise inhibit air flow through the opening and into the inner volume of the shell 3. In FIG. 15, for example, the comforter 35 is shown fully closing the opening 23. As illustrated therein, the comforter 35 can extend beneath and beyond all of the edge portions 24, 26, 28, 30 defining the opening 23 to fully close the opening. In such a configuration, air movement through the opening 23 and into the inner volume of the shell 3 is inhibited. During use of the sleeping bag, the user, including the user's head, would be fully enclosed by the combination of the comforter 35 and the shell 3.

In FIG. 16, the comforter 35 is illustrated partially closing the opening. More specifically, the comforter 35 extends beneath and beyond the lower edge portion 26, the right edge portion 28, and the left edge portion 30 defining the opening. In addition, the illustrated configuration of the comforter 35 extends beneath and beyond the upper edge portion 24 of the shell 3 defining the opening 23. This configuration, allows the user to partially close the opening 23 without covering or fully covering the user's head. Accordingly, the user can manually manipulate the comforter 35 to close the opening 23 entirely or to close the portions of the opening not occupied by the user's face and/or head.

Due to the flexibility of the shell 3, the shape of the opening 23 will change as a result of movement by a user within the inner volume of the shell 3. The comforter 35 and opening 23 are both sized and shaped to inhibit the comforter from closing the opening during use. Moreover, the comforter 35 can be manipulated by the user independently of the shell 3. Thus, during use of the sleeping bag 1, the user can move the comforter 35 relative to the shell 3. As a result, the user can wrap portions of themselves with the comforter 35 or the comforter can overlie the user in a generally flat configuration.

The comforter 35 can be selectively moved to a third position wherein the comforter is almost fully disposed outside the inner volume of the shell. In this third, exterior position, the comforter 35 is pivoted almost 180 degrees, overlying the middle portion 9 and foot portion 7 of the shell. In such a position, the comforter 35 is generally face-to-face with the outer layer 29 of the overlying portion 11 of the shell 3. In this configuration, the comforter 35 adds additional covering for the user's torso and legs. In one suitable embodiment, the comforter 35 has a length sufficient to fully cover the foot portion 7 and middle portion 9 of the shell 3 when in the third, exterior position. FIGS. 10 and 11 do not depict the comforter 35 fully spread out. It is contemplated that the comforter 35 can have different lengths without departing from the scope of this invention. Moreover, the opening 23 is substantially free of the comforter when the comforter is moved to its exterior position.

As seen in FIGS. 12-14, the comforter 35 includes a pair of spaced pockets 37 for receiving the arms and hands of the user to thereby provide added warmth to the arms and hands of the user. The pockets 37 can be used in both the interior and exterior position of the comforter 35. The user can use the pockets 37 to manipulate the comforter 35. That is, the user can place one or both arms in the pockets 37 and thereby move the comforter 35 as desired. In the illustrated embodiment, the pockets 37 extend almost the entire length of the comforter 35. It is contemplated that the length of the pockets 37 relative to the length of the comforter 35 can be varied. It is also contemplated that the pockets 37 can be omitted from the comforter 35 in some embodiments.

The illustrated comforter 35, including the pockets 37, is made from the same material as the shell 3 (i.e., an inner layer, an outer layer, and an insulation material between the inner and outer layers) but it is understood that the comforter can be made from any suitable material or materials. It is also contemplated that the pockets 37 can be formed from materials different than the shell 3 and/or the comforter 35.

FIGS. 17-22 show another embodiment of a zipperless sleeping bag, designated in its entirety by the reference number 101. The sleeping bag 101 comprises an elongate shell, indicated generally at 103, that defines an inner volume sized and shaped to receive a user therein. The shell 103 has a head portion 105, a foot portion 107, and a middle portion 109 extending longitudinally between the head and foot portions (FIG. 18). In addition, the shell 103 has an overlying portion 111, which is adapted to overlie the user during use, and an underlying portion 113, which is adapted to underlie the user during use. The shell 103 further comprises a head end panel 115 located in the head portion 105, a foot end panel 117 located in the foot portion 107, and a pair of spaced side panels 119 located in the middle portion 109. The side panels 119 extend longitudinally between the head end panel 115 and the foot end panel 117. The head end panel 115, the foot end panel 117, and the side panels 119 are stitched into the shell 103 between the overlying portion 111 and underlying portion 113. The shell 103 of sleeping bag 101 tapers from a larger width at the head portion 105 to a smaller width at the foot portion 107. A foot box 141 for selectively receiving the feet of a user is located in foot portion 107 of sleeping bag 101.

A hood, indicated generally at 121, is located at the head portion 105 of the shell 103. The hood 121 is adapted to receive and surround the head of a user. The overlying portion 111, and more specifically the hood 121 in the illustrated embodiment, includes an opening 123. The opening 123 is defined by a continuous inner edge having an upper edge portion 124, a lower edge portion 126, and two side edge portions 128, 130 (i.e., a right side edge portion 128 and a left side edge portion 130 as viewed in FIG. 18). The opening 123 is a general oval shape, meaning the upper edge portion 124 is slightly longer than the lower edge portion 126 and the side edge portions 128, 130 are longer than both the upper and lower edge portions. Due to the length of the side edge portions 128, 130, the opening 123 spans most of the head portion 105. The size and shape of the opening 123 facilitate easier user ingress to and egress from the inner volume of the sleeping bag 101.

Both the overlying portion 111 and the opening 123 are sized and shaped to cooperatively inhibit the edges of the overlying portion 111 defining the opening from folding over during use of the sleeping bag 101. The opening 123 is defined entirely on the overlying portion 111 of the shell 103 and spaced inward from the side panels 119 and head end panel 115. This spacing and the shape of the opening 123 prevents the opening from being expanded or otherwise increase even when the shape of the opening changes as a result of movement by the user within the inner volume of the shell 103. For example, when a portion of the continuous inner edge is displaced, the overlying portion 111 adjacent the opposite portion of the continuous inner edge will resist the movement. Accordingly, the opening 123 will be deformed but will be prevented from opening further. Moreover, the continuous inner edge, which defines the opening 123, is inhibited from folding over onto the overlying portion 111 of the shell 103.

When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A sleeping bag comprising: an elongate shell defining an inner volume sized and shaped to receive a user therein, the shell having a head portion, a foot portion, a middle portion extending longitudinally between the head and foot portions, an overlying portion adapted to overlie the user during use, and an underlying portion adapted to underlie the user during use; and a hood being located in the head portion of the shell, the hood including a catenary opening such that the overlying portion of the shell adjacent the opening is spaced from the underlying portion of the shell when the sleeping bag is laid out for use.
 2. The sleeping bag as set forth in claim 1 wherein the opening in the hood is one of oval, ovate, elliptical or circular.
 3. The sleeping bag as set forth in claim 1 wherein the shell is free from zippers, the opening in the hood providing a user ingress to and egress from the inner volume of the shell.
 4. The sleeping bag as set forth in claim 1 wherein the shell further comprises a head end panel, a foot end panel, and a pair of spaced side panels extending longitudinally between the head end panel and the foot end panel.
 5. The sleeping bag as set forth in claim 4 wherein the opening in the head portion of the shell is spaced from each of the side panels and the head end panel.
 6. A sleeping bag comprising: an elongate shell defining an inner volume sized and shaped to receive a user therein, the shell having an overlying portion adapted to overlie the user during use, an underlying portion adapted to underlie the user during use; and an opening disposed on the overlying portion of the shell, the opening being configured to provide a user ingress to and egress from the inner volume of the sleeping bag, the opening having a width less than a width of the shell.
 7. A sleeping bag as set forth in claim 6 wherein the opening is a rounded opening.
 8. The sleeping bag as set forth in claim 7 wherein the opening is one of oval, ovate, elliptical or circular.
 9. The sleeping bag as set forth in claim 6 wherein the shell further comprises a head end panel, a foot end panel, and a pair of spaced side panels extending longitudinally between the head end panel and the foot end panel, the opening being spaced from the foot end panel and each of the side panels.
 10. The sleeping bag as set forth in claim 9 wherein the opening is spaced from about 7 inches to about 12 inches from each of the side panels.
 11. The sleeping bag as set forth in claim 9 wherein the opening is spaced from the head end panel.
 12. The sleeping bag as set forth in claim 11 wherein the opening is spaced from about 4 inches to about 13 inches from the head end panel.
 13. A sleeping bag comprising: an elongate shell defining an inner volume sized and shaped to receive a user therein, the shell having an overlying portion adapted to overlie the user during use, an underlying portion adapted to underlie the user during use, and an opening disposed on the overlying portion of the shell; and a comforter attached to the overlying portion of the shell for selectively closing the opening.
 14. The sleeping bag as set forth in claim 13 wherein the comforter has a width greater than a width of the shell.
 15. The sleeping bag as set forth in claim 13 wherein the comforter is made from the same material as the shell.
 16. The sleeping bag as set forth in claim 13 wherein the comforter is permanently attached to the shell.
 17. The sleeping bag as set forth in claim 13 wherein the comforter is removably attached to the shell.
 18. The sleeping bag as set forth in claim 13 wherein the comforter has a length less than a length of the shell.
 19. The sleeping bag as set forth in claim 13 wherein the comforter is selectively moveable from an interior position wherein the comforter is disposed in the inner volume of the shell and an exterior position wherein the comforter is at least partly disposed outside the inner volume of the shell and overlies at least part of the middle portion of the shell.
 20. The sleeping bag as set forth in claim 19 wherein the comforter is generally face-to-face with the outer layer of the overlying portion of the shell in the exterior position.
 21. The sleeping bag as set forth in claim 20 wherein the comforter has a length approximately one-half the length of the shell.
 22. A comforter for use with a sleeping bag, the comforter including a pair of longitudinally extending pockets.
 23. The comforter set forth in claim 22 wherein the pockets are sized and shaped for receiving the arms and hands of a user.
 24. The comforter set forth in claim 22 in combination with a sleeping bag, the comforter being attached to the sleeping bag. 